Tag: Full Image Copy

Posted on

2017-08 Anomalies detected in MERGECOPY and MODIFY Recovery

Db2 z/OS Utilities: Identify and avoid some MERGECOPY or MODIFY Recovery anomalies

Just a little note this month about a strange anomaly in the way MERGECOPY and MODIFY RECOVERY seem to work. Let’s begin with MERGECOPY.

1 – MERGECOPY to the death

How many IICs to change a lightbulb?

I was doing some tests, to see how many Incremental Image Copies you can take before RECOVER dies, about 71 by the way, and found this out…

SCRATCHing my head

I did a Full Image Copy, then various updates, and three Incremental Image Copies. Due to bad luck, my Full Image Copy was “accidentally” scratched… Whoops!

MERGECOPY runs

I ran the MERGECOPY and look what happened:

DSNU000I    199 10:37:11.20 DSNUGUTC - OUTPUT START FOR UTILITY, UTILID = DC10MC00MCU012
DSNU1044I   199 10:37:11.21 DSNUGTIS - PROCESSING SYSIN AS EBCDIC
DSNU050I    199 10:37:11.23 DSNUGUTC - MERGECOPY TABLESPACE R510D0DC.R510S81 NEWCOPY YES
DSNU463I    199 10:37:11.30 DSNUYBR3 - THE PRIMARY IMAGE COPY DATA SET SETEMP.R510D0DC.R510S81.P0000.D17195.T1734 WITH
DATE=170714 AND TIME=174140
            IS PARTICIPATING IN MERGECOPY.
DSNU463I    199 10:37:11.37 DSNUYBR3 - THE PRIMARY IMAGE COPY DATA SET SETEMP.R510D0DC.R510S81.P0000.D17198.T1025 WITH
DATE=170717 AND TIME=102429
            IS PARTICIPATING IN MERGECOPY.
DSNU463I    199 10:37:11.43 DSNUYBR3 - THE PRIMARY IMAGE COPY DATA SET SETEMP.R510D0DC.R510S81.P0000.D17198.T1235 WITH
DATE=170717 AND TIME=123501
            IS PARTICIPATING IN MERGECOPY.                                                                   
DSNU463I    199 10:37:11.48 DSNUYBR3 - THE PRIMARY IMAGE COPY DATA SET SETEMP.R510D0DC.R510S81.P0000.D17111.A10756 WITH
DATE=170421 AND TIME=075641
            IS PARTICIPATING IN MERGECOPY.
DSNU030I    199 10:37:11.50 DSNUYBR3 - UNABLE TO ALLOCATE SETEMP.R510D0DC.R510S81.P0000.D17111.A10756, RC=4,
CODE=X'17080002' 
DSNU454I    199 10:37:11.63 DSNUYBR0 - COPY MERGE COMPLETE 
            NUMBER OF COPIES=4        
            NUMBER OF COPIES MERGED=3   
            TOTAL NUMBER OF PAGES MERGED=363 
            ELAPSED TIME=00:00:00  
DSNU010I    199 10:37:11.67 DSNUGBAC - UTILITY EXECUTION COMPLETE, HIGHEST RETURN CODE=4

Look again

Did you see what went wrong? No, nor did I the first time! Review again…

When a Return Code = 04 is actually important

Now do you see it?

DSNU030I    199 10:37:11.50 DSNUYBR3 - UNABLE TO ALLOCATE
SETEMP.R510D0DC.R510S81.P0000.D17111.A10756, RC=4,
CODE=X'17080002'

Hidden amongst all the other output…and “only” a RC=4 !

So? What does that have to do with me?

Well, who checks RC=04? Your data is non-recoverable, but you *think* you are green! Pretty nasty if you ask me! Db2 does get a bonus point though for actually merging the incrementals into another incremental…

2 – MODIFY Recovery

DSNUM ALL gone forever?

Remember the bad old days, when you *had* to take a TS level Image Copy of partitioned objects when you REORGed them?

Wasn’t that a terrible time? Terabytes of disk space pointlessly being filled with needless image copy data. Then along came Db2 11, which enabled TP level copies! Hoorah! Ok, not so hot with tapes etc. but who cares, it worked! Finally, we did not need to keep *huge* DSNUM ALL style copies lounging around on our expensive disks.

Too good to be true?

All sounds good, huh? What did we forget? I will tell you… NPSIs (The indexes formally known as NPIs) What is the problem, I hear you shout! Well, let me walk you through a normal scenario with COPY YES indexes…

Keep it Simple Stupid

Let us imagine a little tablespace with two partitions, one DPSI and two NPSIs. All of the indexes are COPY YES. Due to the fact that we now only do INLINE COPYs at the TP level, SYSCOPY gets lots of records looking like this:

SpacePartType
TP1F
IP1F
TP2F
IP2F
NPSI10F
NPSI20F
Then a day later
TP2F
IP2F
NPSI10F
NPSI20F
Then another day later
TP2F
IP2F
NPSI10F
NPSI20F

Remember that the NPSIs are copied with the DPSIs.

Time to DELETE the old data

Now, using MODIFY RECOVERY, you wish to rid yourself of the oldest data from Part 2.

A nice little

MODIFY RECOVERY TABLESPACE DB.TP DSNUM 2 RETAIN LAST(1)

Is enough. However, as it says in the documentation, this form does *not* delete NPSI data.

 

COPY PEND is not your friend!

If you use the DSNUM ALL, which *will* delete the NPSI data, then it will most probably put the entire table space into COPY PEND, which you do *not* want!

Space is the problem

So now the problem begins to appear… imagine that this has been happening for a year or more… you now have hundreds of syscopy entries *and* datasets for NPSI data that you cannot simply, or easily, MODIFY “away” anymore!

What I think is needed, is a new parameter, say “INCLUDE NPSI”, which will also get rid of NPSI data. RFE anyone??

I have no fix for this problem either, except to actually take a DSNUM 0 copy, including all indexes, and then do DSNUM ALL style MODIFY RECOVERY. Pretty messy…

 

As usual, if you have any comments or queries please feel free to drop me a line!

TTFN

 

Roy Boxwell

Posted on

2017-07 Let’s make Db2 z/OS IMAGE COPY great again!

War story :

Why is Db2 z/OS IMAGE COPY very useful in the current Db2 z/OS world?

Please excuse the heading, I simply could not resist…

This month is another war story from the trenches of Production DBAs fighting the fight for 24×7 Shops around the world…
This time it was a request to recover some tables to a specific point in time that started the ball rolling…

Staged too soon? Bad updates and deletes

The developers pushed some software to production and then found out, five hours later, that there was a logical error and it was doing really bad updates and deletes in a bunch of tables that it should *not* have done. This is bad news…

Backup system to the Rescue?

This firm uses System Level Backup (SLB), but the DBA group, I kid you not, did not know this little factoid (they had alternate facts to works with), and so when the request to restore tables x, y and z to a specific Point in Time (PiT) arrived, they simply created the required RECOVER control cards and, after checking that the tables, indexes and tablespaces were not being used, submitted the RECOVER jobs. Now, the first job worked fine, but the second and the third “bought the farm” with *very* weird messages that the DBA group did not really understand:

RECOVER Messages you do not want to see – Part one

DSNU1520I   319 08:26:44.64 DSNUCBRT - THE RECOVERY BASE FOR TABLESPACE ROYDB.ROYTS DSNUM 1 IS THE SYSTEM LEVEL BACKUP WITH DATE = 20161212, TIME 041302, AND TOKEN X'FF..FF'

DSNU1522I   319 08:26:46.85 DSNUCBRT - THE DFSMSHSM CALL TO RESTORE TABLESPACE ROYDB.ROYTS DSNUM 1 FAILED WITH RC = X'0000005D' AND REASON CODE = X'00000042' SEE THE JOB LOG FOR DFSMSHSM MESSAGES INDICATING THE CAUSE OF THE ERROR

DSNU832I  )DSJP 319 08:26:44.61 DSNUCARS - INDEX ROYSCHEMA.ROYINDEX PARTITION 1 IS IN REBUILD PENDING STATE

DSNU560I  )DSJP 319 08:26:46.87 DSNUGSRX - TABLESPACE ROYDB.ROYTS PARTITION 1 IS IN RECOVER PENDING STATE

DSNU012I    319 08:26:46.88 DSNUGBAC - UTILITY EXECUTION TERMINATED, HIGHEST RETURN CODE=8

(Some names have been changed to protect the innocent!)

Naturally I have added the red and bold highlights. Now this message *really* upset everyone…Why? The tablespaces were previously all RW and OK, but now they were COPY Pending status!

Go Figure!

So what just happened? Well Db2 detected that there was actually an SLB that could be used for the base of this recovery, and so “asked” HSM to get it “back”. It failed with Return Code (RC) X’5D’ decimal 93 and Reason Code X’42’ decimal 66. I love that 42! And with the great “tip” to “Read the Job Log”. The DBA group were a “tad” unhappy about the fact that a *failed* RECOVER set the tablespace in question to COPY Pending by the way!

Where on Earth?

So the DBAs started trying to read the Job Log and could not see anything. They have a 16-way data-sharing group running on 14 separate LPARs… There is *lots* of “job log”…

Eventually under one of 14 different STCs all called “HSM” I found this info:

RECOVER Messages you do not want to see – Part two

08.26.44 S0998158  ARC1801I FAST REPLICATION DATA SET RECOVERY IS STARTING FOR DATA SET QA1B.DSNDBC.ROYDB.ROYTS.J0001.A001, AT 08:26:44 ON 2016/12/12

08.26.46 S0998158  ARC0624I PHYSICAL DATA SET COPY OF VOLUME QA1B.DSNDBC.ROYDB.ROYTS.J0001.A001 TERMINATED PRIOR TO COMPLETION, DFSMSDSS FAILING RC = 8

08.26.46 S0998158  ARC1860I THE FOLLOWING 0001 DATA SET(S) FAILED DURING FAST REPLICATION DATA SET RECOVERY:QA1B.DSNDBC.ROYDB.ROYTS.J0001.A001, COPYPOOL=DSN$LOCDS0P$DB, DEVTYPE=DASD, VOLUME=WSPS95, ARC1166, RC=0

08.26.46 S0998158  ARC1802I FAST REPLICATION DATA SET RECOVERY HAS COMPLETED FOR DATA SET QA1B.DSNDBC.ROYDB.ROYTS.J0001.A001, AT 08:26:46 ON 2016/12/12, FUNCTION RC=0008, MAXIMUM DATA SET RC=0093

So here we see that it failed for RC=0093 (Now in decimal) but with a DFSMSDSS RC = 08

Confused? You will be…

I have not yet found what an RC = 0093 means – My best guess at the moment, is that the data had been “moved” since the SLB, and so the VOLUME swap failed due to some reason or other. The tablespace and index were unavailable and the “window of change” was closing fast…

Can I run backwards out the door?

Panic was approaching when I mentioned they could do the “backwards” LOGAPPLY (BACKOUT YES) and so with high hopes we attempted it, only to see that it sadly died a death if you have COPY Pending status – We felt pretty recursive at this point…

So that left us with one last chance and that was to tell RECOVER to ignore SLB and go directly to an earlier (RESTOREBEFORE) IC with a TORBA syntax.

Hoorah!

We had to wait awhiles but we got there! The RECOVERs all ran though clean and all was well… <phew>

Where’s the Beef?

So “What’s the point?” I hear you muttering… quite simple really:

1- Never rely on SLB to always work

2- Make sure you test it before switching your objects to COPY Pending by accident

3- Still take good old fashioned Image Copies

4- Use of BACKOUT YES can save your bacon *if* you know about it

As usual, if you have any comments or queries please feel free to drop me a line!

 

TTFN

Roy Boxwell

 

More about Utility Management and Space Management: See our RTDX suite of tools

 

Posted on

2016-10 Discovering hidden recovery problems in the SYSLGRNX

A query to read the SYSLGRNX

This month I want to have a look inside the SYSLGRNX – Not just for fun but actually to see if I, and you, have a serious RECOVER problem.

The Problem began with too many TP Image Copy steps

The problems all began when it was noticed by one of our customers that our DB2 Utility generation software (RTDX) was generating Image Copy jobs for “old” PBG partitions that were no longer being updated and they asked us why we were recommending an Image Copy.

RTDX and Image Copy

RTDX (RealTime DBAExpert for z/OS and SAX – Space AssuranceExpert) is threshold based and uses the Real-time Statistics (RTS) tables as the major driver of decisions about REORG, RUNSTATS, and IMAGE COPY. The normal rules for Image Copy are “If the RTS COPY counters have not been updated then there has not been an update and we do not need a Copy”. This is normally extended with a special copy rule “But generate a Full Image Copy every xx days even if no updates”. This is done to guarantee that you can perform a recovery even if your non-DB2 migration/back-up software automatically deletes datasets older than xx days.

Everything green?

So you think you are covered? Not so fast! When the RTS were first introduced back in DB2 V7 they were not that stable and, sometimes, the RTS DB was actually stopped. This meant that the numbers were sometimes “not that reliable” – Now for REORG and RUNSTATS it does not really matter because, at some point, the counters start to count again and all is OK. But for IMAGE COPY it would be a disaster to “miss” an update! RTDX handles this with an extra “belt and braces” or, for the Americans amongst us, “belt and suspenders” check: “CHECK SYSLGRNX? Y/N” setting. If set to “Y” then RTDX generates an extra job that extracts the SYSLGRNX data and loads it into a DB2 table. This can then be queried by RTDX to see when objects were opened for update (Just like DB2 does in RECOVER processing to get the required log ranges.)

Something Old Something New

So now you know how the system works I can explain what happened at the customer site. They use Partition By Growth tablespaces (PBGs) a lot as “containers” to just insert records into. They had PBGs with hundreds of partitions and they wondered why RTDX generated Image Copy steps for partitions 1 – 136 when they only held “old non-changed data”.

Check the code

First thing I did was to check the code for any silly mistakes. Everything was fine. I then got the SYSLGRNX extract file and saw that the Partitions were indeed in there… I then worked with the customer directly using log prints and tracing until we finally saw what was happening.

PBG doing the ripple!

When a new partition was added, all of the previous partitions header pages got an update “max no. of partitions”. Now this update counts as a system page and so is *not* in the RTS Counters as they only count data pages! RECOVER of course does not care! It would demand to look for the log ranges and what would happen if your logs have been deleted? Yep – Unrecoverable data!

APAR PI60104 fixes the problem

So you can apply the APAR and all is good? Not really. You still have to go and check if you have any potentially unrecoverable PBG datasets out there. How do you do that? Well – you ask me!

Reading SYSLGRNX is not so easy

The problem with SYSIBM.SYSLGRNX is that the data is nearly unusable when you want to join to the DB2 Catalog. E.g. Two byte character fields that actually contain SMALLINT values and, sometimes, with the high bit set…

Just creating a table and then a dumb INSERT INTO SELECT FROM dies because of the DSNDB01 Cursor rules. So first you’ll need to create your new version of SYSLGRNX:

-- CREATE NEW VERSION OF SYSLGRNX WITH SMALLINTS --
CREATE TABLE BOXWELL.SYSLGRNX2
   (LGRDBID          SMALLINT          NOT NULL
   ,LGRPSID          SMALLINT          NOT NULL
   ,LGRUCTS          TIMESTAMP         NOT NULL
   ,LGRSRBA          CHAR(10)          FOR BIT DATA NOT NULL
   ,LGRSPBA          CHAR(10)          FOR BIT DATA NOT NULL
   ,LGRPART          SMALLINT          NOT NULL
   ,LGRSLRSN         CHAR(10)          FOR BIT DATA NOT NULL
   ,LGRELRSN         CHAR(10)          FOR BIT DATA NOT NULL
   ,LGRMEMB          SMALLINT          NOT NULL
   ,LGRNEGPSID       CHAR(1)           NOT NULL)
;
COMMIT ;

Cross loader to the rescue!

After trying various tricks to get at the data I hit on the idea of abusing the cross loader to do it for me. Here is my JCL that you must tailor for your site to do the dirty deed:

//LOAD EXEC PGM=DSNUTILB,REGION=32M,PARM='DC10,LOAD' 
//STEPLIB  DD DISP=SHR,DSN=DSNC10.SDSNEXIT.DC10 
//         DD DISP=SHR,DSN=DSNC10.SDSNLOAD 
//SYSUT1   DD UNIT=SYSDA,SPACE=(CYL,(9,9)) 
//SORTOUT  DD UNIT=SYSDA,SPACE=(CYL,(9,9)) 
//SYSERR   DD UNIT=SYSDA,SPACE=(CYL,(9,9)) 
//SYSMAP   DD UNIT=SYSDA,SPACE=(CYL,(9,9)) 
//SYSDISC  DD UNIT=SYSDA,SPACE=(CYL,(9,9)) 
//UTPRINT  DD SYSOUT=* 
//SYSPRINT DD SYSOUT=* 
//SYSIN    DD * 
EXEC SQL 
DECLARE C1 CURSOR FOR 
SELECT COALESCE( 
       CASE WHEN ASCII(SUBSTR(A.LGRDBID, 1, 1)) * 256         
               + ASCII(SUBSTR(A.LGRDBID, 2, 1)) > 32767 THEN  
                (ASCII(SUBSTR(A.LGRDBID, 1, 1)) * 256         
               + ASCII(SUBSTR(A.LGRDBID, 2, 1))) - 32768      
            ELSE ASCII(SUBSTR(A.LGRDBID, 1, 1)) * 256         
               + ASCII(SUBSTR(A.LGRDBID, 2, 1))               
       END , 0)         AS LGRDBID                            
      ,COALESCE(                                              
       CASE WHEN ASCII(SUBSTR(A.LGRPSID, 1, 1)) * 256         
               + ASCII(SUBSTR(A.LGRPSID, 2, 1)) > 32767 THEN  
                (ASCII(SUBSTR(A.LGRPSID, 1, 1)) * 256         
               + ASCII(SUBSTR(A.LGRPSID, 2, 1))) - 32768      
            ELSE ASCII(SUBSTR(A.LGRPSID, 1, 1)) * 256         
               + ASCII(SUBSTR(A.LGRPSID, 2, 1))               
       END , 0)         AS LGRPSID                            
      ,TIMESTAMP(                                             
           CASE WHEN SUBSTR(A.LGRUCDT, 5 , 2 ) > '83' THEN '19'
                ELSE '20'                                     
           END CONCAT                                         
           SUBSTR(A.LGRUCDT, 5 , 2 ) CONCAT '-' CONCAT        
           SUBSTR(A.LGRUCDT, 1 , 2 ) CONCAT '-' CONCAT        
           SUBSTR(A.LGRUCDT, 3 , 2 ) CONCAT '-' CONCAT        
           SUBSTR(A.LGRUCTM, 1 , 2 ) CONCAT '.' CONCAT        
           SUBSTR(A.LGRUCTM, 3 , 2 ) CONCAT '.' CONCAT        
           SUBSTR(A.LGRUCTM, 5 , 2 ) CONCAT '.' CONCAT        
           SUBSTR(A.LGRUCTM, 6 , 2 ) CONCAT '0000'            
                 )      AS LGRUCTS                            
      ,A.LGRSRBA                                              
      ,A.LGRSPBA                                              
      ,A.LGRPART                                              
      ,A.LGRSLRSN                                             
      ,A.LGRELRSN                                             
      ,ASCII(SUBSTR(A.LGRMEMB, 2, 1)) AS LGRMEMB              
      ,CASE WHEN ASCII(SUBSTR(A.LGRPSID, 1, 1)) * 256         
               + ASCII(SUBSTR(A.LGRPSID, 2, 1)) > 32767 THEN ‘Y’
            ELSE ‘N’                                          
       END              AS LGRNEGPSID                         
FROM SYSIBM.SYSLGRNX A                                        
ENDEXEC                                                               
LOAD DATA INCURSOR(C1) RESUME NO SHRLEVEL NONE REPLACE                    
  INTO TABLE BOXWELL.SYSLGRNX2                                        
/*
The use of ASCII is to “translate” the character data into smallint and also to detect if we have negative numbers. This happens if you run out of DBIDs and also if you use CLONE objects. The requirement for the two COALESCEs is down to the cross loader syntax check on the CASE statements by the way…

This could load a lot of data of course!

Do not forget the INDEX

Now the Index that we need to speed up the processing (and the RUNSTATS of course!)

-- CREATE INDEX ON THE COLUMNS WE NEED --
CREATE INDEX BOXWELL.SYSLGRNX_IX
          ON BOXWELL.SYSLGRNX2
       (LGRDBID,LGRPSID,LGRPART,LGRMEMB)
        USING STOGROUP SYSDEFLT
             PRIQTY -1
             SECQTY -1
        CLUSTER
        CLOSE YES
;
COMMIT ;

And the RUNSTATS

RUNSTATS  TABLESPACE <yourdatabase>.<yourtablespace>
          TABLE (ALL)
          INDEX(ALL)
          FREQVAL NUMCOLS 1 COUNT 100 BOTH
          FREQVAL NUMCOLS 2 COUNT 100 BOTH
          FREQVAL NUMCOLS 3 COUNT 100 BOTH
          SHRLEVEL CHANGE REPORT NO UPDATE ALL HISTORY NONE

Now we can SQL So finally we have the SYSLGRNX data in a format that we can actually use! Here is my SQL that lists out any PBG spaces that have, according to the RTS, no updates but the last Image Copy timestamp is earlier than the SYSLGRNX record:

-- FINALLY THE QUERY TO SEE IF A PROBLEM EXISTS OR NOT --
--
-- SELECT ALL PBGS IN SYSTABLESPACE THAT HAVE DATA IN THE
-- SYSLGRNX WHICH ALSO HAVE AN ENTRY IN THE RTS WHERE THE
-- COUNTERS ARE NULL OR ZERO BUT THE COPYLASTTIME IS EARLIER
-- THAN THE SYSLGRNX TIMESTAMP.
--  THIS MEANS THAT THE RTS THINKS "NO REASON TO COPY"
--  BUT SYSLGRNX THINKS "SOMETHING WAS UPDATED"
--

SELECT A.DBNAME, A.NAME, B.LGRPART, A.DBID, A.OBID, A.PSID
      ,B.LGRUCTS, B.LGRSRBA, B.LGRSPBA, B.LGRSLRSN
      ,B.LGRELRSN, HEX(B.LGRMEMB) AS MEMBER
      ,C.COPYLASTTIME
      ,MAX(D.START_RBA) AS HIGHEST_IC_RBA
      ,MAX(D.TIMESTAMP) AS HIGHEST_IC_TS
FROM SYSIBM.SYSTABLESPACE A
INNER JOIN
    BOXWELL.SYSLGRNX2    B
 ON  A.DBID     = B.LGRDBID
 AND A.PSID     = B.LGRPSID
 AND A.INSTANCE = B.LGRINST
INNER JOIN
     SYSIBM.SYSTABLESPACESTATS C
 ON  C.DBID     = A.DBID
 AND C.PSID     = A.PSID
 AND C.PARTITION= B.LGRPART
 AND C.INSTANCE = A.INSTANCE
LEFT OUTER JOIN
     SYSIBM.SYSCOPY       D
  ON D.DBNAME    = A.DBNAME
 AND D.TSNAME    = A.NAME
 AND D.DSNUM   IN ( 0 , B.LGRPART)
WHERE A.TYPE   = 'G'
 AND (C.COPYUPDATEDPAGES = 0
  OR C.COPYUPDATEDPAGES IS NULL)
 AND (C.COPYCHANGES = 0
  OR C.COPYCHANGES IS NULL)
 AND (C.COPYLASTTIME < B.LGRUCTS
  OR C.COPYLASTTIME IS NULL)
 AND (D.ICTYPE = 'F'
  OR D.ICTYPE IS NULL)
GROUP BY A.DBNAME, A.NAME, B.LGRPART, A.DBID, A.OBID, A.PSID
     ,B.LGRUCTS, B.LGRSRBA, B.LGRSPBA, B.LGRSLRSN
     ,B.LGRELRSN, HEX(B.LGRMEMB)
     ,C.COPYLASTTIME
ORDER BY 1 , 2 , 3 , 7
WITH UR
;

And the winner is?

I hope you have zero records returned? Even if you do have some records, it is relatively easy to quickly get them image copied so that you can sleep at night. If zero, you still have a great copy of the SYSLGRNX that you can use for other purposes!

A customer replies

Here’s some real data back from a customer:

discovering hidden recovery problems in the SYSLGRNX; DB2 z/OS; PBG partition

The COUNT is the number of SYSLGRNX entries they have – So they have nine DB & TS groups and from a further analysis (removing the data sharing member duplicates) they have 1926 distinct DB, TS and Partitions!

They scheduled image copy processing for all of these and were then done.

I hope you liked this month’s topic.

As always, any questions or comments would be most welcome!

TTFN,

Roy Boxwell

Posted on

2016-04 DB2 SYSCOPY – Do you know what is in it? Redux

DB2 10, DB2 11 Migration & DB2 Database maintenance

A special query to check and clear out the DB2 Catalog

 

This is a redux of my original Newsletter from February 2013 with additional data at the very end – The reason for this relaunch? Simple – I have had numerous emails about this topic, especially with regard to migrating from DB2 10 to DB2 11, and it is obviously still very important to check and to clear out *before* you start your DB2 migration. So now enjoy the redux version…

 

DB2 Database Maintenance and the DB2 Catalog

If you have written your own DB2 database maintenance programs then you almost certainly run SQL queries against the DB2 Catalog. If you are also checking for Incremental Image Copies (IIC) or Full Image Copies (FIC) then you will probably be using a mix of Real-Time Statistics tables (RTS) and the SYSIBM.SYSCOPY to figure out which type of utility to generate. Further if you are in DB2 10 (any mode! CM8, CM9, or NF) then this newsletter is for you!

 

I had a problem in one of our test centers with a cursor that I noticed was taking a long time to finish and so I went into our Analyze+ tool and extracted the EDM Pool data (this is the new data in DB2 10 NF that is synonymous with the Dynamic Statement Cache counters and statistics) and sorted by Total Elapsed Time descending to get this:

 

Analyze+ for DB2 z/OS ----- EDM Pool (6/12) -------- Stmt 1 from 316 
Command ===>                                         Scroll ===> CSR  
                                                           DB2: QA1B 
Primary cmd: END, SE(tup), Z(oom), L(ocate) 
             total elapse time                 
Line    cmd: Z(oom), A(nalyze), D(ynamic Analyze), E(dit Statement), 
             P(ackage), S(tatement Text)
                                                               
                     Total       Average         Total       Average
     StmtID   Elapsed Time  Elapsed Time      CPU Time      CPU Time
----------- HHHH:MM:SS.ttt HHH:MM:SS.ttt HHH:MM:SS.ttt HHH:MM:SS.ttt
     115967    1:28.107705     29.369235   1:12.151391     24.050464
     114910       8.367834      0.000331      6.779229      0.000268
      79642       7.998559      0.054412      6.346829      0.043176
     114907       5.760045      0.000238      4.378691      0.000181
     115974       5.031890      2.515945      2.937258      1.468629
       5439       4.037261      0.000739      2.685938      0.000492

 

Over one hour total and over 29 minutes average for our small amount of test data set alarm bells ringing – so I drilled down to the SQL:

 

Analyze+ for DB2 z/OS -- View EDM-Pool Statement LINE 00000001 COL 001 080
Command ===>                                             Scroll ===> CSR
                                                         DB2: QA1B
Primary cmd: END
Collection:RTDX0510_PTFTOOL
Package   :M2DBSC09 
Contoken  :194C89620AE53D88  PrecompileTS: 2012-10-29-15.34.40.938230
StmtID    :          115967  StmtNo      :      1223  SectNo:       2
---------------------------------------------------------------------
DECLARE
  SYSCOPY-IC-MODI-9N
CURSOR WITH HOLD FOR 
SELECT                                                                       
  T1.N1 , T1.N2 , T1.N3 , T1.N4 , T1.N5 , T1.N6 , T1.N7 , T1.N8 , T1.N9 
  , T1.N10 , T1.N11 , T1.N12 
FROM (
  SELECT       
    ICTS.DBNAME AS N1
  , ICTS.TSNAME AS N2
  , ICTS.TIMESTAMP AS N3
  , ' ' AS N4
  , ICTS.DSNUM AS N5
 , ICTS.ICTYPE AS N6
 , DAYS ( :WORK-CURRENT-DATE ) - DAYS ( ICTS.TIMESTAMP ) AS N7
 , ICTS.OTYPE AS N8
 , ICTS.DSNAME AS N9
 , ICTS.ICUNIT AS N10
 , ICTS.INSTANCE AS N11
 , ICTS.STYPE AS N12                                                                    
  FROM SYSIBM.SYSCOPY ICTS                                                     
  WHERE ICTS.ICBACKUP IN ( '  ' , 'LB' , 'FC' )                            
  AND  ICTS.OTYPE = 'T' 
  UNION                    
   SELECT                           
    ICIX.DBNAME AS N1
  , CAST ( TABLES.TSNAME AS CHAR ( 8 ) CCSID EBCDIC ) AS N2
  , ICIX.TIMESTAMP AS N3
  , ICIX.TSNAME AS N4
  , ICIX.DSNUM AS N5
  , ICIX.ICTYPE AS N6
  , DAYS ( :WORK-CURRENT-DATE ) - DAYS ( ICIX.TIMESTAMP ) AS N7
  , ICIX.OTYPE AS N8
  , ICIX.DSNAME AS N9
  , ICIXS.ICUNIT AS N10
  , ICIX.INSTANCE AS N11
  , ICIX.STYPE AS N12
   FROM SYSIBM.SYSCOPY ICIX
      , SYSIBM.SYSINDEXES INDEXES
      , SYSIBM.SYSTABLES TABLES           
   WHERE ICIX.ICBACKUP IN ( '  ' , 'LB' , 'FC' )                          
   AND  ICIX.OTYPE = 'I' 
   AND VARCHAR ( ICIX.DBNAME , 24 ) = INDEXES.DBNAME       
   AND VARCHAR ( ICIX.TSNAME , 24 ) = INDEXES.INDEXSPACE 
   AND INDEXES.TBNAME = TABLES.NAME
   AND INDEXES.TBCREATOR = TABLES.CREATOR           
   AND  TABLES.TYPE IN ( 'H' , 'M' , 'P' , 'T' , 'X' ) )    
 AS T1                                                   
 ORDER BY CAST (T1.N1 AS CHAR ( 8 ) CCSID EBCDIC )
        , CAST (T1.N2 AS CHAR ( 8 ) CCSID EBCDIC )
        , N3 DESC 
 FOR FETCH ONLY       
 WITH UR                                                             



 HOSTVARIABLE NAME             NULLABLE  TYPE           LENGTH  SCALE
 ---------------------------  --------  --------------  -----  -----
 WORK-CURRENT-DATE             NO        CHAR              26       
 WORK-CURRENT-DATE             NO        CHAR              26       
******************************** Bottom of Data **********************

 

Ok, ok this SQL is not going to win a beauty contest any day soon but it used to run just fine…so now I explained it:

Analyze+ for DB2 z/OS -- Explain Data (1/6) --------- Entry 1 from 7  
Command ===>                                         Scroll ===> CSR   
EXPLAIN: DYNAMIC     MODE: CATALOG                         DB2: QA1B  
Primary cmd: END, T(Explain Text), V(iolations), R(unstats), 
             P(redicates), S(tatement Text), C(atalog Data),
             M(ode Catalog/History),Z(oom), PR(int Reports), 
             SAVExxx, SHOWxxx
             
Line    cmd: Z(oom), C(osts), I(ndexes of table), S(hort catalog),
             T(able), V(irtual indexes of table), 
             X(IndeX)                               
Collection : RTDX0510_PTFTOOL   Package : M2DBSC09   Stmt :     1223
Version    : - NONE -         
Milliseconds:  77519  Service Units: 220222  Cost Category: B
                                                                                
  QBNO QBTYPE CREATOR  TABLE NAME       MTCH IX METH PRNT TABL PRE  MXO 
  PLNO TABNO  XCREATOR INDEX NAME ACTYP COLS ON OD   QBLK TYPE FTCH PSQ 
  ---- ------ -------- ---------- ----- ---- -- ---- ---- ---- ---- --- 
     1 SELECT R510PTFT T1         R        0 N     0    0 W    S      0 
     1 5 
     1 SELECT                              0 N     3    0 -           0 
     2 0  
     2 UNION                               0       3    1 -           0 
     1 0 
     3 NCOSUB SYSIBM   SYSCOPY    R        0 N     0    2 T    S      0 
     1 1         
     4 NCOSUB SYSIBM   SYSCOPY    R        0 N     0    2 T    S      0 
     1 2        
     4 NCOSUB SYSIBM   SYSINDEXES I        2 N     1    2 T           0 
     2 3      SYSIBM   DSNDXX02       
     4 NCOSUB SYSIBM   SYSTABLES  I        2 N     1    2 T           0 
     3 4      SYSIBM   DSNDTX01      
  ---- ------ -------- ---------- ----- ---- -- ---- ---- ---- ---- ---

 

This is *after* I had REORGed the SYSCOPY, SYSTSIXS and SYSTSTAB and then run the RUNSTATS on the SYSTSIXS and SYSTSTAB as you cannot do inline RUNSTATS on those two of course!

 

Two tablespace scans against the SYSCOPY is not brilliant of course but in this system we only have 4,000 table spaces and 2,500 indexes… so then I used the Catalog primary command to have another look at the catalog data:

TS   : DSNDB06 .SYSCOPY 
Stats: 2013-02-04-10.49.32.600316 
  Partitions:  0 , Tables: 1 , NACTIVEF: 18.272 pages 
  Type      :  Neither a LOB nor a MEMBER CLUSTER.
  RTS data TOTALROWS : 347.087 , Pages: 18.268
              
Table: SYSIBM.SYSCOPY 
Stats: 2013-02-04-10.49.32.600316
  No. of rows (CARDF): 347.082 , Pages: 18.268 
  Index: SYSIBM.DSNUCH01 
  Stats: 2013-02-04-10.49.32.600316     Type: Type-2 index
    Levels: 3 , Leaf pages: 3.945 
    FIRSTKEYCARDF: 101 , FULLKEYCARDF: 347.082 
    RTS data Levels: 3 , Leaf pages: 3.945 , TOTALENTRIES: 347.087 
    CLUSTERING: Y , CLUSTERED: Y , CLUSTERRATIO = 100,00% 
    DATAREPEATFACTORF: 18.268 
    Indexcolumn  ! Format        ! Dist. Values ! A/D ! NL ! Stats  
    -------------+---------------+--------------+-----+----+-------
    DBNAME       ! CHAR(8)       !          101 ! ASC ! N  ! OK  
    TSNAME       ! CHAR(8)       !          712 ! ASC ! N  ! OK  
    START_RBA    ! CHAR(6)       !       72.398 ! DSC ! N  ! OK  
    TIMESTAMP    ! TIMESTAMP(6)  !      347.082 ! DSC ! N  ! OK  
                                                                               
  Index: SYSIBM.DSNUCX01                                                 
  Stats: 2013-02-04-10.49.32.600316   Type: Type-2 index 
    Levels: 3 , Leaf pages: 509
    FIRSTKEYCARDF: 1.820 , FULLKEYCARDF: 1.820
    RTS data Levels: 3 , Leaf pages: 509 , TOTALENTRIES: 347.087 
    CLUSTERING: N , CLUSTERED: Y , CLUSTERRATIO = 100,00%
    DATAREPEATFACTORF: 18.275 
    Indexcolumn  ! Format        ! Dist. Values ! A/D ! NL ! Stats 
    -------------+---------- ----+--------------+-----+----+-------
    DSNAME       ! CHAR(44)      !        1.820 ! ASC ! N  ! OK    
                                                

Here I had a heart attack! 347,087 rows?!?!?!?!?!? How in the wide wide world of sports did that happen? Time to drill down into the contents of SYSCOPY with this little query:

SELECT ICTYPE , STYPE,  COUNT(*) 
FROM SYSIBM.SYSCOPY  
GROUP BY ICTYPE , STYPE            
;

Which returned these rather surprising results:

---------+---------+---------+
ICTYPE  STYPE                          
---------+---------+---------+
A       A                4             
B                       46             
C       L             1669             
C       O                4             
F                      100             
F       W               16             
I                        4             
L       M           344723             
M       R               18             
R                      151             
S                       62             
W                       18             
W       S                1             
Y                        2             
Z                      269             
DSNE610I NUMBER OF ROWS DISPLAYED IS 15

The L and M combination appears 344,723 times!!!

Grab your handy DB2 10 SQL reference and page on down to DB2 Catalog tables, SYSIBM.SYSCOPY and you will see:

ICTYPE CHAR(1) NOT NULL

Type of Operation:

A ALTER
B REBUILD INDEX
C CREATE
D CHECK DATA LOG(NO) (no log records for the range are available for RECOVER utility)
E RECOVER (to current point)
F COPY FULL YES
I COPY FULL NO
L SQL (type of operation)
M MODIFY RECOVERY utility
P RECOVER TOCOPY or RECOVER TORBA (partial recovery point)
Q QUIESCE
R LOAD REPLACE LOG(YES)
S LOAD REPLACE LOG(NO)
T TERM UTILITY command
V REPAIR VERSIONS utility
W REORG LOG(NO)
X REORG LOG(YES)
Y LOAD LOG(NO)
Z LOAD LOG(YES)

Now in my version the L entry has a ‘|’ by it to signify it is new. Scroll on down further to STYPE to read

STYPE CHAR(1) NOT NULL

Sub-type of operation:

When ICTYPE=L, the value is:

M Mass DELETE, TRUNCATE TABLE, DROP TABLE, or ALTER TABLE ROTATE PARTITION.
The LOWDSNUM column contains the table OBID of the affected table.

So, in other words, every time a program does a MASS DELETE it inserts a row into SYSCOPY. So then I ran another query to see when this all began and, hopefully, ended:

SELECT MAX(ICDATE), MIN(ICDATE) 
FROM SYSIBM.SYSCOPY                   
WHERE ICTYPE = 'L'                    
;                                     
---------+---------+---------+--------
                                      
---------+---------+---------+--------
121107  120828                        
DSNE610I NUMBER OF ROWS DISPLAYED IS 1

 

So we started getting records on the 28th August 2012 and the last one was the 7th November 2012 so in just about ten weeks even we managed 344,723 Mass Deletes!

So now, with my Sherlock Holmes deer stalker hat on, the question was “Why did it stop in November?” Happily we have a history here of APARs and that’s when this PMR bubbled to the Surface:

PM52724: MASS DELETES ENDS UP WITH LOCK ESCALATION ON SYSCOPY IN V10. BECAUSE PM30991 INTALLED CODE INSERTING L 12/01/04 PTF PECHANGE

 

I will let you go and read the text but suffice it to say IBM realized what a disaster this “logging” of Mass Deletes was and HIPERed a quick fix to stop it! Plus you can see the APAR that “brought in the dead mouse” PM30991.

PM30991 UK66327 Closed 2011-03-30

PM52724 UK80113 Closed 2012-07-03

So if you installed the PM30991 and not the PM52724 you probably have some cleaning up to do…

By the way I also rewrote the Ugly Duckling SQL:

  SELECT  T1.N1      
         ,T1.N2         
         ,T1.N3              
         ,T1.N4         
         ,T1.N5        
         ,T1.N6       
         ,T1.N7 
         ,T1.N8      
         ,T1.N9     
         ,T1.N10         
         ,T1.N11        
         ,T1.N12       
    FROM (                                   
   SELECT ICTS.DBNAME    AS N1   
         ,ICTS.TSNAME    AS N2      
         ,ICTS.TIMESTAMP AS N3      
         ,' '            AS N4     
         ,ICTS.DSNUM     AS N5     
         ,ICTS.ICTYPE    AS N6     
         ,DAYS ( :WORK-CURRENT-DATE ) - DAYS ( ICTS.TIMESTAMP ) AS N7
         ,ICTS.OTYPE     AS N8             
         ,ICTS.DSNAME    AS N9               
         ,ICTS.ICUNIT    AS N10              
         ,ICTS.INSTANCE  AS N11              
         ,ICTS.STYPE     AS N12              
     FROM SYSIBM.SYSCOPY ICTS                
    WHERE ICTS.ICBACKUP IN ('  ','LB','FC')  
      AND ICTS.OTYPE    = 'T'
UNION ALL    
   SELECT ICIX.DBNAME     AS N1    
         ,CAST(TABLES.TSNAME                 
          AS CHAR(8) CCSID EBCDIC) AS N2  
         ,ICIX.TIMESTAMP  AS N3      
         ,ICIX.TSNAME     AS N4
         ,ICIX.DSNUM      AS N5              
         ,ICIX.ICTYPE     AS N6              
         ,DAYS ( :WORK-CURRENT-DATE ) - DAYS ( ICIX.TIMESTAMP ) AS N7
         ,ICIX.OTYPE      AS N8              
         ,ICIX.DSNAME    AS N9               
         ,ICIX.ICUNIT    AS N10              
         ,ICIX.INSTANCE  AS N11              
        ,ICIX.STYPE     AS N12                
    FROM SYSIBM.SYSCOPY ICIX                  
        ,SYSIBM.SYSINDEXES INDEXES            
        ,SYSIBM.SYSTABLES TABLES              
   WHERE ICIX.ICBACKUP IN ('  ','LB','FC')    
     AND ICIX.OTYPE        = 'I'              
     AND ICIX.DBNAME      = INDEXES.DBNAME    
     AND ICIX.TSNAME      = INDEXES.INDEXSPACE
     AND INDEXES.TBNAME    = TABLES.NAME      
     AND INDEXES.TBCREATOR = TABLES.CREATOR   
 ) AS T1                                      
ORDER BY CAST(T1.N1 AS CHAR(8) CCSID EBCDIC)  
        ,CAST(T1.N2 AS CHAR(8) CCSID EBCDIC)  
        ,        N3 DESC                      
  FOR FETCH ONLY                              
  WITH UR                                     
  ;

 

To now perform like this:

Milliseconds:  55911  Service Units:   158836  Cost Category: A 
                                                                                 
QBNO QBTYPE CREATOR  TABLE NAME       MTCH IX METH PRNT TABL PRE  MXO 
PLNO TABNO  XCREATOR INDEX NAME ACTYP COLS ON OD   QBLK TYPE FTCH PSQ 
---- ------ -------- ---------- ----- ---- -- ---- ---- ---- ---- ---
   1 NCOSUB SYSIBM   SYSINDEXES I        0 N    0     2 T    S      0 
   1 3      SYSIBM   DSNDXX07   
   1 NCOSUB SYSIBM   SYSTABLES  I        2 N    1     2 T           0 
   2 4      SYSIBM   DSNDTX01
   1 NCOSUB SYSIBM   SYSCOPY    I        2 N    1     2 T    S      0 
   3 2      SYSIBM   DSNUCH01    
   2 UNIONA                              0 N    3     0 -           0 
   1 0   
   5 NCOSUB SYSIBM   SYSCOPY    R        0 N    0     2 T    S      0 
   1 1         
   ------ -------- ----------  ------ ---- -- ---- ---- ---- ----- ---

 

I am sure once I have deleted all the SYSCOPY rows (Note that we do not need to RECOVER on our test machine so I have the luxury of being able to delete the data – You, of course, cannot!) that it will return to being a nice little SQL!

 

After a large DELETE run which left only 2,365 rows followed by a REORG with inline RUNSTATS the original SQL now looks like:

 

Milliseconds:       672  Service Units:       1909  Cost Category: B  
                                                                               
QBNO QBTYPE CREATOR  TABLE NAME       MTCH IX METH PRNT TABL PRE  MXO
PLNO TABNO  XCREATOR INDEX NAME ACTYP COLS ON OD   QBLK TYPE FTCH PSQ
---- ------ -------- ---------- ----- ----- ---- -- ---- ---- ---- --
   1 SELECT R510PTFT T1         R        0 N     0    0 W    S      0
   1 5   
   1 SELECT                              0 N     3    0 -           0
   2 0   
   2 UNION                               0       3    1 -           0
   1 0 
   3 NCOSUB SYSIBM   SYSCOPY    R        0 N     0    2 T    S      0
   1 1  
   4 NCOSUB SYSIBM   SYSCOPY    R        0 N     0    2 T    S      0
   1 2  
   4 NCOSUB SYSIBM   SYSINDEXES I        2 N     1    2 T           0
   2 3      SYSIBM   DSNDXX02                 
   4 NCOSUB SYSIBM   SYSTABLES  I        2 N     1    2 T           0
   3 4      SYSIBM   DSNDTX01      
  ---- ------ -------- ------------------ ----- ---- -- ---- ---- ----

And my version:

Milliseconds:      631  Service Units:     1792  Cost Category: A          
                                                                                
QBNO QBTYPE CREATOR  TABLE NAME       MTCH IX METH PRNT TABL PRE  MXO
PLNO TABNO  XCREATOR INDEX NAME ACTYP COLS ON OD   QBLK TYPE FTCH PSQ
---- ------ -------- ---------- ----- ---- ---- -- ---- ---- ---- ---- 
   1 NCOSUB SYSIBM   SYSCOPY    R        0 N     0    2 T    S      0
   1 2       
   1 NCOSUB SYSIBM   SYSINDEXES I        2 N     1    2 T           0
   2 3      SYSIBM   DSNDXX02  
   1 NCOSUB SYSIBM   SYSTABLES  I        2 N     1    2 T           0
   3 4      SYSIBM   DSNDTX01 
   2 UNIONA                              0 N     3    0 -           0
   1 0             
   5 NCOSUB SYSIBM   SYSCOPY    R        0 N     0    2 T    S      0
   1 1   
   ---- ------ -------- ------------------ ----- ---- -- ---- ---- ----

Doesn’t look quite so impressive now…sniff…sniff

 

Here’s my SYSCOPY query for all cases:

SELECT ICTYPE, STYPE, MIN(ICDATE) AS OLDEST, MAX(ICDATE) AS NEWEST
     , COUNT(*) AS COUNT                                          
FROM SYSIBM.SYSCOPY                                               
GROUP BY ICTYPE , STYPE                                           
;                                                                 
---------+---------+---------+---------+---------+
ICTYPE  STYPE  OLDEST  NEWEST        COUNT           
---------+---------+---------+---------+---------+
A       A      121228  121228            4        
B              121228  130128           46       
C       L      100809  130204         1669    
C       O      120827  120827            4    
F              100809  130204          100     
F       W      100809  130204           16   
I              130131  130204            4
M       R      130102  130131           18         
R              120829  130130          151        
S              120829  130131           62      
W              100809  130204           18       
W       S      100809  100809            1     
Y              120828  120828            2    
Z              120828  130201          269    
DSNE610I NUMBER OF ROWS DISPLAYED IS 14

 

Clean Up

OK, so what can you do if you have 1000’s of these records? Well I would start with MODIFY RECOVER utilities to delete the bad guys. Your “normal” DB2 Database Maintenance jobs should take care of this for you but if you do not run these on a regular basis then start with this query:

SELECT A.DBNAME, A.TSNAME, A.DSNUM                              
      , MAX(DATE(A.TIMESTAMP)), MIN(DATE(A.TIMESTAMP)), COUNT(*)
FROM SYSIBM.SYSCOPY A                                           
WHERE A.ICTYPE = 'L'                                            
  AND A.STYPE  = 'M'                                            
  AND EXISTS (SELECT 1                                          
              FROM SYSIBM.SYSCOPY B                             
              WHERE A.DBNAME = B.DBNAME                         
                AND A.TSNAME = B.TSNAME                         
                AND (A.DSNUM  = B.DSNUM                         
                 OR (A.DSNUM > 0                                
                 AND B.DSNUM = 0 ))                             
                AND A.START_RBA < B.START_RBA                   
                AND B.ICTYPE = 'F')                             
GROUP BY A.DBNAME, A.TSNAME, A.DSNUM                            
FOR FETCH ONLY                                                  
WITH UR                                                         
;

The output shows you the DBNAME, TSNAME, DSNUM and counts for all of the “bad guys” that have at least one Full Image Copy *after* the bad guy was inserted:

---------+---------+---------+---------+---------+---------+---------+
DBNAME    TSNAME          DSNUM                                       
---------+---------+---------+---------+---------+---------+---------+
R510D0PT  R510S04             0  2016-01-26  2015-11-11           75  
R510D0PT  R510S10             0  2016-01-26  2015-11-11           75  
R510D0PT  R510S12             0  2016-01-26  2015-11-11           75  
R510D0PT  R510S14             0  2016-01-26  2015-11-11           75

 

This gives you the needed input to write a simple MODIFY RECOVER utility input like this:

 

MODIFY RECOVERY TABLESPACE R510D0PT.R510S04 DELETE DATE 20151203

Why did I use 2015-12-03 when in the query output I have 2015-11-11? That’s because I do not want to delete *all* of the Image Copy data in SYSCOPY – just the data from 2015-11-11 to 2015-12-02 (remember that MODIFY works up to the date *before* you enter). The output from the MODIFY looked like this:

 

DSNU000I    028 09:10:43.97 DSNUGUTC - OUTPUT START FOR UTILITY, 
            UTILID = PTFMO000MOU001
DSNU1044I   028 09:10:44.16 DSNUGTIS - PROCESSING SYSIN AS EBCDIC
DSNU050I    028 09:10:44.17 DSNUGUTC -  MODIFY RECOVERY TABLESPACE
            R510D0PT.R510S04 DELETE DATE 20151203
DSNU517I    -QA1B 028 09:10:44.28 DSNUMDEL 
            - SYSCOPY RECORD DELETED BY MODIFY UTILITY.
DSN=SETEST.R510D0PT.R510S04.D15142.T0635, VOL=SER=(CATLG), FILESEQNO=0
DSNU575I   -QA1B 028 09:10:44.49 DSNUMODA - MODIFY COMPLETED SUCCESSFULLY
DSNU010I    028 09:10:44.52 DSNUGBAC - UTILITY EXECUTION COMPLETE, 
            HIGHEST RETURN CODE=0

 

Now you must also IDCAMS Delete any, and all, of the dataset names output here.

Now re-running the original query gives:

---------+---------+---------+---------+---------+---------+---------
DBNAME    TSNAME          DSNUM                                      
---------+---------+---------+---------+---------+---------+---------
R510D0PT  R510S04             0  2016-01-26  2015-12-03           53 
R510D0PT  R510S10             0  2016-01-26  2015-11-11           75 
R510D0PT  R510S12             0  2016-01-26  2015-11-11           75 
R510D0PT  R510S14             0  2016-01-26  2015-11-11           75

 

24 type L & M records gone from between 2015-11-11 and 2015-12-02 and of course the object is not in COPY Pending status!

However, there are cases where you cannot do this straightaway (Perhaps never been image copied?). In these cases, the simplest method is to do an Image copy and then a Modify, but if the object is to big then you must make the DB2 Catalog updateable (ask your friendly Sysprog about this,) and simply use an SQL DELETE to remove all of the entries for an object *before* the last Full Image Copy.

Once you have removed all the fluff, remember to REORG SYSCOPY and RUNSTAT the indexes. Then it should be a *lot* thinner and make migrating a tad easier!

 

As always if you have any comments or questions please email me!

TTFN

Roy Boxwell